Gas-phase S-alkylation of benzenethiol with aliphatic alcohols, ethers, esters, alkyl halides and olefins over halide cluster catalysts of Groups 5 and 6 transition metals
Gas-phase S-alkylation of benzenethiol with aliphatic alcohols, ethers, esters, alkyl halides and olefins over halide cluster catalysts of Groups 5 and 6 transition metals
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DOI：
10.1016/j.apcata.2012.09.053
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发表时间：
2013-01
影响因子：
5.5
通讯作者：
S. Nagashima;Kentaro Kudo;H. Yamazaki;S. Kamiguchi;T. Chihara
中科院分区：
文献类型：
--
作者：
S. Nagashima;Kentaro Kudo;H. Yamazaki;S. Kamiguchi;T. Chihara
以硅胶为载体，[（Nb 6Cl 12）Cl 2（H2O）4]·6 H2O为催化剂，在氢气流下使苯乙胺与甲醇反应。簇的催化活性在高于250°C时开始，产生甲基苯基硫醚。在400°C下选择性为98%。具有相同八面体金属骨架的钼、钽和钨卤化物簇也催化了该反应。具有较短烷基链的伯醇是有效的S-烷基化试剂。脂肪族醚、碳酸二烷基酯、原酸酯和卤代烷是有效的S-烷基化试剂。当将1-己烯应用于反应时，自发和催化S-烷基化在200°C以上同时进行，产生正己基苯基硫醚。当乙酸烷基酯进行此反应时，铌簇合物生成S-苯硫代乙酸酯，而其它簇合物选择性地生成烷基苯硫醚。一个布朗斯台德酸网站归因于羟基配体，这是通过热活化形成的簇合物上，提出作为催化剂的活性位点。
Benzenethiol was reacted with methanol under a hydrogen stream over [(Nb6Cl12)Cl2(H2O)4]·6H2O supported on silica gel. Catalytic activity of the cluster commenced above 250°C, yielding methyl phenyl sulfide. The selectivity was 98% at 400°C. Molybdenum, tantalum and tungsten halide clusters with the same octahedral metal framework also catalyzed the reaction. Primary alcohols with shorter alkyl chains were effective reagents for the S-alkylation. Aliphatic ethers, dialkyl carbonates, orthoesters and alkyl halides were effective reagents for the S-alkylation. When 1-hexene was applied to the reaction, spontaneous and catalytic S-alkylation proceeded simultaneously above 200°C, yielding n-hexyl phenyl sulfide. When alkyl acetates were subjected to this reaction, the niobium cluster afforded S-phenyl thioacetate, and the other clusters afforded alkyl phenyl sulfides selectively. A Brønsted acid site attributable to a hydroxo ligand, which is formed on the cluster complex by thermal activation, is proposed as the active site of the catalysts.